In general, ink jet printing machines or printers include at least one printhead that ejects drops or jets of liquid ink onto a recording or image forming media. A phase change ink jet printer employs phase change inks that are solid at typical room temperatures, but melt to become a liquid at elevated temperatures. The melted ink can then be ejected by a printhead directly onto an image receiving substrate, or onto an intermediate imaging member for transfer to an image receiving substrate. Once the ejected ink is on the image receiving substrate, the ink droplets quickly solidify to form an image.
In some phase change ink imaging devices, the image receiving substrates are individual sheets of recording media. The sheets are typically stored in one or more supply trays and retrieved, one at a time, for image processing. This type of printer is very effective for customized image renderings and document production. In other phase change ink imaging devices, the image receiving substrate is a web of recording media that is continuously fed into the printer on a path that transports the media past the printheads for reception of an image and then transported to an output area. In some web printers, the web is rewound onto a take-up roll. When the entire web has been imaged, the take-up roll is removed and taken elsewhere for further processing. In other web printers, the web is cut into individual sheets that are ejected into a collection bin.
Webs printed by phase change ink printers receive more than the images that are rendered for production. In addition to the ink images, the printer controller ejects ink in images or patterns outside of an image area on the web. In some cases, this extra area includes part of the image that is cut off because the printed image goes up to the edge of the cut sheet. These patterns may also include test patches for evaluating colors being generated by the printheads, fiducials for alignment verification, and other non-document image patterns. In the printers in which the printed media is cut at the end of the printing process, these non-document image patterns may present issues. If the patterns are positioned in the inter-document areas between document images, the cutter may have to cleave the solidified ink in the non-document image patterns. Because melted phase change ink solidifies rather quickly after being ejected, it does not bleed into the media. This property enables images formed on the print media with phase change ink to exhibit bright, vibrant colors. Cutting this solidified ink, however, may cause the solidified ink to break or flake off the media. Reducing the debris arising from the ink fragments is a worthwhile goal in solid ink printers.